volcanic eruptions can destroy propertics and kill people

TRUE OR FALSE​

Answer:

The net calorific value of the fuel 1 is 40000 kilojoules per kilogram.

The net calorific value of the fuel 2 is 50000 kilojoules per kilogram.

Explanation:

The net calorific value is equal to the heat produced ([tex]Q[/tex]), in kilojoules, divided by the mass of the burnt fuel ([tex]m[/tex]). We proceed to calculate the net calorific value of each fuel:

Fuel 1 ([tex]m = 4\,kg[/tex], [tex]Q = 160000\,kJ[/tex])

[tex]L = \frac{160000\,kJ}{4\,kg}[/tex]

[tex]L = 40000\,\frac{kJ}{kg}[/tex]

The net calorific value of the fuel 1 is 40000 kilojoules per kilogram.

Fuel 2 ([tex]m = 2\,kg[/tex], [tex]Q = 100000\,kJ[/tex])

[tex]L = \frac{100000\,kJ}{2\,kg}[/tex]

[tex]L = 50000\,\frac{kJ}{kg}[/tex]

The net calorific value of the fuel 2 is 50000 kilojoules per kilogram.

Answer:

The pressure on piston 1 is always equal to the pressure on piston 2. ... It is equal to the force on piston 1, multiplied by A2/A1. Hydraulic systems are called force multipliers for exactly this reason. A small force can be increased by using hydraulics

Explanation:

Radhe Radhe❤

1. set up the equation

2. multiply the variables

3. analyze your results

Answer:

Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events

Answer:

The comparison of an unknown quantity with a known quantity is called measurement

Answer:

1.17

Explanation:

Given that,

The refractive index of ice wrt air = 1.31

The refractive index of rock salt wrt air = 1.54

We need to find the refractive index of rock salt with respect to ice.

We know that,

refractive index = (speed of light in air or vaccum)/( speed of light in that medium)

So,

The speed of light in ice = c/(1.31)

The speed of light in rock salt = c/(1.54)

So, the refractive index of rock salt with respect to ice​ is :

[tex]\mu=\dfrac{1.54}{1.31}\\\\=1.17[/tex]

So, the required refractive index of rock salt wrt ice is 1.17.

Answer:

  (D)  4

Explanation:

The percentage error in each of the contributors to the calculation is 1%. The maximum error in the calculation is approximately the sum of the errors of each contributor, multiplied by the number of times it is a factor in the calculation.

  density = mass/volume

  density = mass/(π(radius^2)(length))

So, mass and length are each a factor once, and radius is a factor twice. Then the total percentage error is approximately 1% +1% +2×1% = 4%.

_____

If you look at the maximum and minimum density, you find they are ...

  {0.0611718, 0.0662668} g/(mm²·cm)

The ratio of the maximum value to the mean of these values is about 1.03998. So, the maximum is 3.998% higher than the "nominal" density.

The error is about 4%.

_____

Additional comment

If you work through the details of the math, you will see that the above-described sum of error percentages is just an approximation. If you need a more exact error estimate, it is best to work with the ranges of the numbers involved, and/or their distributions.

Using numbers with uniformly distributed errors will give different results than with normally distributed errors. When such distributions are involved, you need to carefully define what you mean by a maximum error. (By definition, normal distributions extend to infinity in both directions.) While the central limit theorem tends to apply, the actual shape of the error distribution may not be precisely normal.

Answer:

Explanation:

#CARRYONLEARNING

justoko2

Answer:

Consequently the statement is FALSE

Explanation:

The process of emission of electrons or photoelectric effect, was explained by Einstein, assuming that light behaves as formed by how many so-called photons and each one of them collides with an electron, therefore to start an electron the incident photon energy must be greater than the work function of the material.

            E =K + Ф

By mentioning the intensity we increase the number of photons but we do not increase their energy.

Consequently the statement is FALSE

Explanation:

First find the area of the entire floor:

Area of a rectangle= length × width

( 4000mm× 3600mm)

14400000mm²

Area of one square tile??= side ×side

12cm×12cm

144cm²

Convert cm to mm

1cm²=100mm²

144cm²=144cm²/1cm²×100mm²

=14,400mm²

Number of tiles required to cover the entire floor= 14400000mm²/14400mm²

=1000

Answer:Whenever the velocity of the object increases or usually doubles, the kinetic energy will be quadrupled. If in case you are not familiar with kinetic energy, this is known as the type of energy that is in motion. The greater the mass of the object, the greater the total of the energy

Explanation:

Change to an object would quadruple its kinetic energy Increasing its velocity to twice its original value

In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest. Formally, kinetic energy is any term in a system's Lagrangian which includes a derivative concerning time.

In classical mechanics, the kinetic energy of a non-rotating object of mass m traveling at a speed v is [tex]{\textstyle {\frac {1}{2}}mv^{2}}[/tex]

In relativistic mechanics, this is a good approximation only when v is much less than the speed of light.

The standard unit of kinetic energy is the joule, while the English unit of kinetic energy is the foot-pound.

Learn more about kinetic energy

https://brainly.com/question/12337396

#SPJ2

Explanation:

Khi một hạt thực hiện SHM Đang chuyển động từ vị trí cực biên về vị trí trung bình, thì vận tốc và gia tốc cùng hướng, tức là hướng về vị trí trung bình

Answer:

A. Mg+2

Explanation:

im not sure, but since it lost two electrons which have a negative charge it gained two charge.

Answer:

Quantity of charge = 80 Coulombs

Explanation:

Given the following data;

Current = 2 A

Time = 40 seconds

To find the amount of charge flowing through the light bulb;

Mathematically, the quantity of charge passing through a conductor is given by the formula;

Quantity of charge = current * time

Substituting into the formula, we have;

Quantity of charge = 2 * 40

Quantity of charge = 80 Coulombs

Answer:

The Reactants                                                       Products                          

Copper sulfate + zinc             →                        Zinc sulfate + copper

aluminum + copper chloride     →                    Aluminum chloride + Copper

Copper + Oxygen                     →                      Copper oxide

Explanation:

The Reactants                                                       Products                          

Copper sulfate + zinc                                        Zinc sulfate + copper

aluminum + copper chloride                            Aluminum chloride + Copper

Copper + Oxygen                                             Copper oxide

First reaction can be described as a single replacement reaction

Second reaction is also a single replacement reaction just like the first reaction

The third is a synthesis reaction ( i.e. reaction in which elements combine to form single compound )

Answer:

Explanation:

I'm assuming you missed the decimal point in the initial velocity and that it should be 4.0 m/s. If after a half of a second it is moving a tiny bit slower, it would be because of air resistance. You can only neglect air resistance if the problems you are doing tell you neglect it.

Answer:

Air resistance

Explanation:

I got it correct on the quiz :)

Answer:

The standard of efficiency varies by product category

these are called BEE star label and they show how much electricity the appliance consumes in year each appliance gets btw one and five stars with five stars meaning that it's extremely efficienct andis likely to keep your electricity bills in check

hope it's helpful

Answer:

7. F

8. T

Explanation:

7. An anion is indicated by a negative superscript charge (- something) to the right of the atom. For example, if a sodium atom loses one electron, it will have one more proton than electron, giving it an overall +1 charge. The chemical symbol for the sodium ion is Na+1 or just Na+

8.Like charges repel each other; unlike charges attract. Thus, two negative charges repel one another, while a positive charge attracts a negative charge. The attraction or repulsion acts along the line between the two charges

1.) False

2.) True

hope this helped,, good luck!! :]

Answer:

88.34 N directed towards the center of the circle

Explanation:

Applying,

F = mv²/r................... Equation 1

F = Force needed to keep the mass in a circle, m = mass of the mass, v = velocity of the mass, r = radius of the circle.

But,

v = 2πr/t................... Equation 2

Where t = time, π = pie

Substitute equation 2 into equation 1

F = m(2πr/t)²/r

F = 4π²r²m/t²r

F = 4π²rm/t²............. Equation 3

From the question,

Given: m = 0.8 kg, r = 0.7 m, t = 0.5 s

Constant: π = 3.14

Substitute these values into equation 3

F = 4(3.14²)(0.7)(0.8)/0.5²

F = 88.34 N directed towards the center of the circle

Answer:

v = 4 m/s

Explanation:

Given :

Ball X :

Mass, m1 = 8kg ;

Initial Velocity, u1 = 2 m/s

Final velocity, v1 = 0

Ball Y:

Mass, m2 = 4kg ;

Initial Velocity, u2 = 0 m/s

Final velocity, v2 = v

(m1u1 + m2u2) = (m2v2 + m1v1)

(8*2 + 4*0) = (4*v + 4*0)

16 + 0 = 4v + 0

16 = 4v

v = 16 / 4

v = 4 m/s

Answer:

Explanation:

This is the Law of Momentum Conservation which for us looks like this:

[tex][m_xv_x+m_yv_y]_b=[m_xv_x+m_yv_y]_a[/tex] and that should look familiar to you if this is what you are doing in physics. Filling in our particular info:

[(8.0 × 2.0)+ (4.0 × 0.0)] = [(8.0 × 0.0) + (4.0v)] and

16 + 0 = 0 + 4.0v and

16 = 4.0v so

v = 4.0 in the direction of ball X

Answer:

Q=21600C

Explanation:

Q=It.

Data

I=12A

t=30min

convert time from minutes to second

t=60*30

=1800s

Q=?

Q=It

=(12A)*(1800s)

Q=21600C

Answer:

22

Explanation:

Answer:

45.5 v

Explanation:

I = 1.3 A

R = 35 Ω

V = I * R

V = 1.3 * 35 = 45.5 v

Answer:

Netball is a ball sport for two teams of seven players it's rules are published in print and online by the international netball federation Games are played on a rectangular court divided into thirds with a raised goal at coach short end

Explanation:

It will help you

Answer:

h2 PRD algo trata gevbjjgcvnkoytewxc.

Answer:

12.5kg

Explanation:

The process is explained in the paper

Answer:

[tex]F=0N[/tex]

Explanation:

From the question we are told that:

Charge [tex]Q=4.88 x 10-6 C[/tex]

Velocity [tex]v= 265m/s[/tex]

Angle [tex]\theta =0 \textdegree[/tex]

Magnetic field [tex]B=0.0579T[/tex]

Generally the equation for Force is mathematically given by

 [tex]F=Q(\=v*\=B)[/tex]

 [tex]F=qvBsin\theta[/tex]

Therefore

 [tex]F=qvBsin0 \textdegree[/tex]

 [tex]F=0N[/tex]

Answer:

0 newtons

Explanation:

When a moving charge is parallel to the magnetic field, it feels no Magnetic force at all.

Even if the Magnetic Field is 100,000,000 Tesla!

Melting: the substance changes back from the solid to the liquid

Evaporation: the process by which water changed from a liquid to a gas.

Boiling: the process by which a liquid turns into a vapor when it is heated to it's boiling point.

Condensation: the substance changed from a gas to a liquid

Freezing: the substance changed from a liquid to solid.

Answer:

Melting is a process that causes a substance to change from a solid to a liquid.

Evaporation is the process of turning from liquid into vapour.

Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the

Condensation is the process of water vapor turning back into liquid water

Freezing is a phase transition where a liquid turns into a solid when its temperature is lowered below its freezing point